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There were 275,896 adults in contact with drug and alcohol services in the UK between April 2020 and March 2021 with substance dependence/addiction issues. These figures may be the tip of the iceberg, as they show people who have sought help with their dependence/addiction issues; however, they do not account for people who have dependence/addiction issues who have not sought help.
Statistics from the show that:
- 16.6% of adults in England report drinking to hazardous levels, while 1.2% report levels which indicate probable alcohol dependence.
- 3.1% of adults in England show signs of drug dependence, and men (4.3%) are more likely to be dependent on illegal drugs than women (1.9%).
- Half of the people with drug dependence received mental health treatment.
- Adults with drug dependence are twice as likely as the general population to use psychological therapy.
Rehab 4 Addiction drug referral service report that:
- Roughly a third of adults had taken a drug at some point in their life.
- 2.4% of adults were frequent drug users, that is, had taken drugs more than once a month in the most recent year (2018/2019).
Rehab Recovery report that in the UK, thousands of people are living with some form of substance abuse or addiction and that drug abuse, alcoholism and other forms of dependency are a big problem, as between 2020 and 2021 over 130,000 people began some form of drug or alcohol dependency treatment in the UK.

What is drug dependence?
Dependence is a state in which a person’s brain and body have become accustomed to the presence of a certain substance which that person has consumed repeatedly over a prolonged period, and requires certain levels of that substance in order to function normally.
Drug dependence can result from prescribed drugs, recreational drugs or medicines available over the counter.
When people use the term “dependence” they are usually referring to a physical dependence on a substance. Dependence is characterised by the symptoms of tolerance and withdrawal. Dependence refers to when the continued use of a drug results in the body adapting to repeated exposure to the drug. When this happens, the brain can only function normally in the presence of the substance.
When someone is unable to function normally and participate in everyday activities such as attending school/college, going to work, and meeting their social and personal needs without taking a particular substance, then they can be described as being dependent on that substance.
Withdrawing from the substance often leads to different physiological and physical reactions, and depending on the substance, withdrawal symptoms vary in severity and can be physically life-threatening. However, abusing a drug which is not physically affecting the way your body works could still lead to suicidal thoughts and severe depression.
How are dependencies classified?
The Diagnostic and Statistical Manual of Mental Disorders (DSM) is the leading source for diagnosing and understanding addiction. The DSM-IV defined abuse and dependence as two separate disorders. However, the most recent edition of the DSM, that is DSM-V, no longer creates this distinction; “Substance Use Disorder” is now the medical term for addiction/dependence.
Previously, abuse was considered a mild form of addiction, and dependence was a moderate or severe form of addiction. DSM-V classifies substance use disorders as mild, moderate or severe, and it doesn’t use the terms “abuse” and “dependence” to categorise the severity of an addiction.
Part of the reason for the change in terminology was the confusion surrounding the word “dependence”; by defining an addiction as a “substance use disorder” takes into account people who may not have a debilitating addiction but who also need help.
Abuse and dependence are defined on a scale that measures the time and degree of substance use. Essentially, abuse is the early stage of dependence, and as substance abuse becomes more frequent, the likelihood of developing a dependence disorder becomes greater.
What are the types of drug dependence?
Some drugs that cause dependence include nicotine, morphine, heroin, also known as diamorphine, cocaine, amphetamine and alcohol. In addition, some people can become dependent upon medicines that are prescribed or bought over the counter from their local pharmacy, such as benzodiazepines, codeine or over-the-counter painkillers.
People who have drug dependence may have psychological dependence and/or physical dependence and/or tolerance to a particular drug. Psychological dependence means that you have a craving or are compelled to use a particular drug to give you pleasure or to stop you from feeling bad, even though it may be dangerous to take the drug. Physical dependence means that if the drug is stopped suddenly you get withdrawal symptoms.
Tolerance is usually a part of dependence. It means that you need more and more of the same drug to give you the same feeling as the smaller amount you used when you first started taking that drug.
What causes drug dependence?
Physical drug dependence appears to occur when repeated use of a drug changes the way the brain feels pleasure. The addicting drug causes physical changes to some nerve cells (neurons) in the brain. Neurons use chemicals called neurotransmitters to communicate. These changes can remain long after you stop using the drug.
Physical drug dependence can start with experimental use of a recreational drug in social situations, and, for some people, the drug use becomes more frequent. For others, particularly with opioids, drug dependence begins when they take prescribed medicines or receive them from others who have prescriptions.
As time passes, they may need larger doses of the drug to get high. Soon they may need the drug just to feel good. As their drug use increases, they may find that it’s increasingly difficult to go without the drug. Attempts to stop drug use may cause intense cravings and make them feel physically ill. These are called withdrawal symptoms.
Mental dependence is when use of a substance is a conditioned response to an event or feeling. These are known as “triggers”. Triggers can be emotional responses to events, certain people, places or anything a person associates with using a substance.
People of any age, sex or economic status can become dependent on a drug, although several factors can affect the likelihood and contribute to the development of drug dependence.
The main factors being:
- Family history of addiction or dependency. Drug dependency is more common in some families and likely involves an increased risk based on genes. Someone who has a blood relative, such as a parent or sibling, with alcohol or drug dependency, may be at greater risk of developing a drug dependency.
- Mental health disorder. If someone has a mental health disorder such as depression, attention-deficit hyperactivity disorder (ADHD) or post-traumatic stress disorder, they are more likely to become dependent on drugs. Using drugs can become a way of coping with painful feelings, such as anxiety, depression and loneliness, and can make these problems even worse.
- Peer pressure is a strong factor in starting to use and misuse drugs, particularly for young people.
- Lack of family involvement. Difficult family situations or lack of a bond with parents or siblings may increase the risk of drug addiction and dependency, as can a lack of parental supervision.
- Early use. Using drugs at an early age can cause changes in the developing brain and increase the likelihood of progressing to drug addiction and dependency.
- Taking a highly addictive drug. Some drugs, such as stimulants, cocaine or opioid painkillers, may result in faster development of addiction and dependency than other drugs. Smoking or injecting drugs can increase the potential for addiction. Taking drugs considered less addicting, so-called light drugs, can start someone on a pathway of drug use, addiction and dependency.

What are the signs and symptoms of drug dependence?
The signs and symptoms of dependence and addictions can vary from person to person and can also depend on the type of dependence that a person is suffering from. However, there are several signs and symptoms that are common to most types of dependence.
These include some or all the symptoms of addiction, which may involve:
- Using drugs despite the consequences.
- Being unable to stop using drugs.
- Neglecting social and work obligations because of drug use.
- Development of a high tolerance for the substance as your body adapts to the drug, leading to a desire for larger or more frequent doses.
- Physical symptoms of withdrawal when you attempt to stop using the drug.
Substance users typically pass through certain stages on the way to dependence.
These stages include:
- Using drugs for recreation. You take them infrequently and in social settings.
- Starting to use drugs on a regular basis, often abandoning family and friends in favour of drug use. You become concerned about losing access to drugs.
- Becoming addicted to drugs as you become more tolerant to their effects and become preoccupied with getting them. You may abandon most or all of your previous interests and relationships.
- Becoming dependent on drugs and unable to live without them. Your physical and mental health deteriorates.
You can often determine if an addiction has turned into dependence by looking at behaviour. When a person addicted to drugs hasn’t had them for a period of time, this can cause a physical reaction. Physical symptoms of withdrawal occur when the body becomes stressed without the drug.
These symptoms include but are not limited to:
- Anxiety.
- Depression.
- Muscle weakness.
- Nightmares.
- Sweating.
- Feeling hot and cold.
- Runny eyes and nose.
- Yawning.
- Being off food.
- Stomach cramps.
- Nausea.
- Vomiting.
- Tremor.
- Poor sleep.
- Restlessness.
- General aches and pains.
- Just feeling awful.
Another significant symptom of substance dependence is when an individual uses a drug in situations where it is dangerous for them to do, such as before driving. This usually extends to using the drug within the workplace and other places where doing so is highly risky.
How is drug dependence diagnosed?
Diagnosing substance dependence is sometimes difficult, particularly when the patient is unhelpful, perhaps seeking to conceal their condition. Commonly, particularly in primary care and emergency care settings, patients consult a clinician for a medical problem without mentioning their drug use or the full extent of any problem use or dependency. Medical professionals are able to make a diagnosis following an in-depth assessment of the patient. This is often known as a dual assessment.
A GP is a good place to start if you feel that you are developing a dependency on drugs and other substances, as they can discuss your problems with you and get you into treatment. They may offer you treatment at the practice or refer you to your local drug service. If you are not comfortable talking to a GP, you can approach your local drug treatment service yourself. As well as the NHS, there are charities and private drug and alcohol treatment organisations that can help you. Links to some are detailed at the end of this article.

How is drug dependence treated?
When drug abuse escalates to dependence, treatment becomes complicated. The person who is dependent must stop using the drug, but doing so abruptly can cause physical symptoms.
Medicines for drug dependence are mainly used to reduce or prevent withdrawal symptoms. In the short term they help to stabilise the person’s drug use and lifestyle while trying to break drug use. In the long term these medicines may help to change the person’s drug taking and any risky behaviour.
Sometimes other medicines may be prescribed in addition to the medicine that helps to treat withdrawal symptoms. Some drug users are often dependent on more than one drug and they may need a combination of medicines to help with dependency.
There are several medicines that are used for drug dependence.
The choice of medicine prescribed will depend on which drug you are dependent on:
- Opiates such as heroin or morphine – Methadone, buprenorphine, lofexidine and naltrexone may be used to treat opiate withdrawal and dependency.
- Stimulants such as cocaine or amphetamines – Benzodiazepines such as diazepam are used to help the patient “come down”. Antidepressants such as fluoxetine and lofepramine may be used to treat any underlying depression. Sometimes a medicine called dexamphetamine is used to treat people who are dependent on amphetamines.
- Alcohol – Chlordiazepoxide is normally used to help at first with acute withdrawal. Carbamazepine or clomethiazole may also be used for acute withdrawal. Haloperidol or olanzapine may be prescribed for hallucinations during acute withdrawal. Acamprosate, naltrexone and disulfiram are used long term to help prevent you from drinking alcohol again.
- Benzodiazepines – A longer-acting benzodiazepine, normally diazepam, is usually prescribed to people who are dependent on short-acting benzodiazepines as this is less likely to produce withdrawal effects. The dose of this can then very slowly be reduced.
- Nicotine – Nicotine replacement therapy (NRT) such as patches, gum and sprays, bupropion, or varenicline may be used to treat nicotine dependency. NRT is best used as part of a smoking cessation programme.
Final thoughts
If left untreated, dependence on drugs can be dangerous. You may increase your drug use as your body adapts to the drugs, which can result in overdose or death. Treatment can reverse dependence, but you must want to be treated. Sometimes, treatment is successful the first time, but relapse is common. Ongoing therapy and support groups can help you recover, stay on track, and address symptoms of relapse.
To speak to someone anonymously about any type of drug dependency you can call the Samaritans free on 116 123.
Call FRANK 24 hours a day, 7 days a week on 0300 123 6600
Alcoholics Anonymous (AA) 0800 9177 650 help@aamail.org (email helpline)
We are with you online chat
Cocaine Anonymous UK 0800 612 0225 helpline@cauk.org.uk
Marijuana Anonymous 0300 124 0373 helpline@marijuana-anonymous.org.uk
Narcotics Anonymous 0300 999 1212
Release 020 7324 2989 ask@release.org.uk (email helpline)